Rotary piston pump and control mechanism therefor



W. M. BEATTY.

ROTARY PISTON PUMP AND CONTROL MECHANISM THEREFOR.

APPLICATION FILED IUNE 1!, I920. I

Patented Dec. 5,

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IN MENTOR WI T/VESSES w. M. BEA TTY. ROTARY PISTON PUMP AND CONTROL MECHANISM THEREFOR.

APPLICATION FILED JUNE H, I920- Patented Dec. 5, 1922.

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WITNESSES W. M. BEATTY.

ROTARY PISTON PUMP AND CONTROL MECHANISM THEREFOR.

APPLELATION FILED JUNE 11, I920.

Patented Dec. 5, 1922,

3 SHEETS-SHEET 3 m m-Tu w/T/vEssEs fiww Patented Dec. 5, 1922.

WILLIAM M. BEATTY, .OF PITTSBURGH, PENNSYLVANIA.

ROTARY PISTON PUMP AND CONTROL MECHANISM THEREFOR.

Application filed. June 11, 1920. Serial No. 388,184.

To all whom it may concern:

Be it known that I, \VILLIAM M. BEATTY, a resident of Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Rotary Piston Pump and Control Mechanism Therefor, of which the following is a specification.

The invention relates to driving mechanism for vehicles and the object thereof is to provide a power unit and mechanism for controlling it whereby a vehicle may be driven at variable speeds both forwardly and rearwardly, and whereby the changes from one speed to another, or from forward to rearward propulsion may be easily affected.

The invention is illustrated in the accompanying sheets of drawings, of which Fig. 1 is a somewhat diagrammatic plan view .of an automobile chassis equipped with the improved power unit and control mechanism; Figs. 2 and 3 sectional views to enlarged scale taken, respectively, on the lines II-II, and TIL-III. Fig. 1; Fig. 4 a sectional view taken on the line IV-IV, Fig. 2; Fig. 5 a vertical central sectional view of a rotary fluid pump, the plane of view being perpendicular to the pump axis; Fi 6 a sectional view taken on the line VI-FI, Fig. 5; and Fig. 7 a perspective view of a detail explained hereinafter.

In the practice of the invention, an internal combustion engine or other suitable prime mover is connected to the rotary element of a radial-cylinder pump of the eccentric piston-supporting shaft type, and such pump is used to supply motive fluid, such as oil under pressure, to fluid motors having driving connection with the vehicle wheels. Control mechanism is provided for shifting the pump shaft to variable eccentric positions for causing the vehicle to be driven either forwardly or rearwardly. The control mechanism preferably includes two independently operated elements for controlling the piston-supporting shaft of the pump, one of such elements being particularly adapted to effect the major control of the shaft in its opposite extreme position, and the other element to effect a gradual intermediate control thereof.

Having reference to the illustrative embodiment of the invention, and particularly to Fig. 1, an automobile chassis 1 is indicated as being provided with the usual front steering wheels 2 and rear wheels 3, and with a prime mover 4 which may be any suitable form of internal combustion engine.

The power shaft 5 of the prime mover is connected to a motive fluid pump, the outer casing of which is indicated at 6, and the construction of which will be presently explained.

Two conduits 7 and 8 connect the pump casing 6 with a fluid manifold 9 havim two fluid compartments 10 and 11, Fig. 3. Zach wheel of the automobile is preferably driven by a separate fluid-actuated motor 12 havmg suitable driving connections between it and the wheel, such connections not being illustrated herein, but being of a sort well understood by those skilled in the art. To each motor 12 there extends from the manifold chambers 10 and 11 a pair of conduits l3 and 14, seen particularly in Figs. 1 and 3, through which conduits pressure-fluid flows to, and exhaust fluid from, the several motors.

As previously stated, the motive fluid pump is preferably of the radial-cylinder eccentric-shaft type. While various motors of this general form maybe used, the preferred construction is particularly illustrated in Figs. 5 and 6. Within the motor casing 6 there is rotatably mounted a disc 15 attached on its central axis to the power shaft 5. The disc is provided with a plurality of radially-disposed cylindrical openings 16, in each of which there is mounted for reciprocation a piston 17, attached,'as by means of a ball and socket joint 18, to a connecting rod 19. As particularly indicated in Fig. 7, the inner end of each connecting rod is attached to a bar 20 forming a segment of a cylinder and provided with oppositely pro- ]ecting lugs 21. The several bars are rotatably held upon a movable shaft 22 by means of straps 60. The pump casing 6 is provided interiorly with a pair of oppositely-disposed inwardly-promoting blocks 23 and 24 which divide the easing into inlet and outlet compartments communicating with the conduits 7 and 8 which, as previously explained, connect the pump casing with the manifold 9.

When the shaft 22 is in the position indicated in Fig. 5 eccentric with respect to the disc 15, the rotation of such disc by the power shaft 5 has the effect of causing oil or other motive fluid to be drawn into the pump casing through the conduit 8, and to be discharged from such casing through the conduit 7. V

To shift the shaft 22 from such indicated position either to a position concentric with the disc 15, or eccentric on the opposite side of the axis of the disc, the mechanism particularly illustrated in Figs. 1, 2, 4 and 6 may be used. The pump casing 6 is provided with a verticall disposed slot 25 through which the shaft 22 projects. The

end of the shaft is provided with an enlarged head 26 screw-threaded interiorly to receive the threaded end of a shaft 27, the other end of which has keyed to it a pinion 28 adapted to mesh with a longitudinally movable rack 31. This rack merges into a tube 32 on which there is keyed or otherwise attached a worm 33, meshing with interior threads formed on the sleeve 34, which sleeve is rotatably mounted upon the end of the tube 32.

To move the tube 34 longitudinally, its end is rovided with an annular groove 35 adapted to be engaged by a yoke 36, pivotally attached as at 37 to a control lever 38 which may be pivoted as at 39 to a fixed point. By moving the hand lever, long1tudinal movement is imparted to the rack 31, the connections being through the yoke 36, sleeve 34, pinion 33 and tube 32. The longitudinal movement of the rack causes the shaft 27 to rotate with a consequent movement of the piston-supporting shaft 22.

While the operating mechanism thus far explained may be used to effect any desired movement of the rack 28 and hence any desired positioning of the movable pump shaft 22, it is preferred to use this mechanlsm primarily for moving the shaft 22 to its opposite extreme eccentric positions. The intermediate positions of the shaft 22 are preferably affected by means of a foot pedal control which will now be explained.

The outer face of the end of the tube 34 is provided with elongate teeth adapted to mesh either with a rack 40 or with a rack 41, depending upon the substantially extreme position of the control mechanism as operated by the hand lever 38. The two racks 40 and 41 form a yoke 42 which 1s longitudinally movable by a foot pedal 43 (Fig. 1) connected to the yoke 42 by the illustrated train of levers. For controlling the yoke 42 to the end that one or the other of the racks 40 and 41 may be in engagement with the teeth on the tube 34, a pair of offset arms 44 and 45 are secured at their ends to the yoke 36. These arms are so formed that they continuously bear upon the exterior faces .of the racks 40 and 41, the arm 44 hearing on the rack 40 and the arm 45 on the rack 41.

In the position of the parts shown in Figs. 2 and 4. the arm 44 holds the rack 40 in engagement with the teeth of the sleeve 34 so that a longitudinal movement of the yoke 42 will cause the sleeve'34 to rotate, and by such rotation the-tube 32 and rack 31 will, through the worm wheel 33, be moved longitudinally. When the hand lever 38 is shifted to its opposite position, the rack 41 will be in engagement with the opposite side of-the tube 34 and the rack 40 will be out of engagement with such tube, with the result that, when the foot pedal 43 is depressed, the tube 34 Will be rotated in the opposite direction from that in which it is rotated when the parts are in the positions shown in Figs. 2 and 4.

An oil storage reservoir 46 may be connected to the manifold 9 by means of conduits 47 and 48, the conduit 47 leading to the manifold chamber 10 and the conduit 48 to the manifold chamber 11. The conduit 47 is divided into two branches, as indicated in Fig. 1, one branch being provided with a suitable intake check valve 49 permitting flow in one direction only from the reservoir 46 to the manifold chamber 10, and the other branch being provided with a suitable relief pressure valve 50 adapted to permit the flow of fluid to the storage reservoir in case the pressure of the fluid rises above a predetermined amount. In a similar way the conduit 48 is formed into two branches provided with an intake check valve 51 and a relief pressure valve 52.

In operation, the prime mover 4 rotates the shaft 5 and thereby imparts rotation to the pump disc 15 with the result that when the shaft 22 is in the eccentric position indicated in Fig. 5 oil will flow into the pump through the conduit 8 and from the pump through the conduit 7. The oil flows from the conduit 7 into the manifold chamber 10 and from such chamber flows through the several conduits 13 to the fluid-motors 12. The spent motive fluid flows from the motors 12 through the conduits 14 into the manifold chamber 11 which is connected by the conduit 8 to the pump casing. By such cycle of flow of motive fluid the vehicle is driven in one direction.

To drive the vehicle in the opposite direction, the shaft 22 of the pump is shifted to a position on the opposite side of the axis of the disc 15, in which the spent motive fluid is taken into the pump through the conduit 7 and discharged therefrom through the conduit 8, the flow through the manifold chambers 10 and 11 and through the conduits 13 and 14 being in the opposite direction from that which has just been explained. It thus appears that either of the pump chambers may be an intake or a discharge chamber.

To shift the shaft 22 to its variable positions, the hand lever 38 is preferably used to move such shaft to one or the other of the extreme eccentric positions, and the foot pedal is used to shift the shaft from one of its extreme eccentric positions to a concentric position, and in such range of movement any desired variation in driving speed and power may be obtained.

The driving mechanism thus explained affords an easily operated and effective control of the vehicle for all variable speeds and for both forward and rearward driving.

According to the provisions of the patent statute, I have described the principle and operation of my invention, togetherwith the construction which I now consider to represent the best. embodiment thereof. However, I desire to have it understood that, within the scope of the appended claims, my invention ma be practiced by other forms of construction than that specifically shown and described herein.

I claim 1. The combination of a radial-cylinder rotary piston-pump provided with a piston support movable to variable eccentric positions and having fluid intake and discharge openings, manually operable means for moving said piston support to its opposite eccentric positions, and separate manually operable means for moving said support to intermediate eccentric positions.

2. The combination of a radial-cylinder rotary piston-pump provided with :a piston support movable to variable eccentric positions and having intake and discharge openings, hand lever mechanism for moving said piston support to its opposite eccentric positlon, and supplementary foot-pedal control means for moving the said support to intermediate eccentric positions.

3. The combination of a radial-cylinder rotary piston-pump provided with a piston support movable to variable eccentric positions, said pump. having intake and discharge openings, a screw-threaded head attached to the end of said piston support, a threaded shaft engaging said head, and means for rotating said shaft to move said support.

4. The combination of a radial-cylinder I K rotary piston-pump provided with a piston support movable to variable eccentric positions and having intake and discharge openings, manually operable connections for moving said support, said connections including a longitudinally movable rack attached at one end to a tube provided with a worm wheel, a tubular worm shaft meshing with said worm wheel, means for moving said wormv shaft longitudinally to adjust said piston support to its opposite eccentric position, and means for rotating said tubular worm shaft for moving said support to intermediate eccentric positions.

5. The combination of a reversible radialcylinder rotary piston-pump provided with a piston support movable to variable eccentric positions and having intake and discharge openings, a fluid supply reservoir, conduits extending from each of said openings to said reservoir, each of said conduits being divided into two branches both of which are connected to said reservoir, one branch of each conduit being provided with a check valve permitting fiow only from the reservoir to the pump and the other branch being provided with a relief pres sure valve.

6. The combination of a reversible fluid pump having a casing provided with two openings acting as intake or discharge openings depending upon the operation of the pump, a fluid supply reservoir, conduits extending from each of said openings to said reservoir, each of said conduits bein divided into two branches both of whic are connected to said reservoir, one branch of each conduit being provided with a check valve permitting flow only from the reservoir to the pump and the other branch being provided with a relief pressure valve. In testimony whereof, I have hereunto set my hand.

WILLIAM M. BEATTY.

Witnesses:

PAUL N. GRrroHLow, HOWARD L. SNIVELY. 

